Solar cells, for example thin film cells such as cells of amorphous silicon, CdTe, GaAs, or other III-V compounds, or cells based on semiconductor compounds such as copper, gallium, and indium diselenide, are based on a stack of layers of photoconverter materials and current collection materials.
Given the difficulty of developing the complete device, it is preferable to take care in choosing the photoconverter material.
To make the best choice of photoconverter material, one determines the optoelectronic properties of the material in order to deduce the efficiency it would be possible to obtain with the complete device.
For this purpose, particularly for thin film technology, it is often necessary to develop specific technological steps to eliminate the influence of contacts which otherwise could influence or even dictate the properties of the contacts/photoconverter material system. Optimization of providing these contacts can therefore be time-consuming without contributing any true added value to the final photovoltaic device, in which laying out contacts is of course necessary but is subject to other technological constraints.
A need therefore exists for a method for directly measuring on the photoconverter material the optoelectronic properties which allow evaluating the efficiency of a solar cell obtained using this photoconverter material, with no need to shape or process the material or laying out the contacts.